#元组 不可修改
dimensions = (200,50)
print(dimensions[0])
print(dimensions[1])

for element in dimensions:
    print(element)

dimensions = (400, 100)
for element in dimensions:
    if 400 == element:
        print(element)
    else:
        print('nothing here')

print(400 in dimensions)
print(400 not in dimensions)


empty_array = []
if empty_array:
    for element in empty_array:
        print(element)
else:
    print("empty array")